If I were in your shoes I would find a way to try and avoid going to the classes. Why waste money on something you know is not going to benefit you? Plus if you show up to the trial class you know they are going to try and sell you on it harder.

Well, you're already going there for the mission right? No one said you can't just casually bump into tai-chi girl while you're attending to church business. For $85 + $45 you'll probably have better success with the local street walkers.